Infants and other incontinent individuals wear disposable absorbent articles such as diapers to absorb and retain urine and other body exudates. Absorbent articles may function both to contain the discharged materials and to isolate these materials from the body of the wearer and from the wearer's garments and bed clothing.
Diapers can be configured to fit on a wearer's body in various ways. For example, some diaper may be configured as pull-on pant-type diapers or training pants. Diapers, such as training pants, may be used with infants prior to and/or during toilet training. Training pants may be configured with a “closed” chassis configuration, in which the chassis is adapted to be pulled on over the legs and lower torso of the wearer without any additional fastening steps.
Closed chassis diapers may be manufactured with a front ear being seamed to a back ear to form the closed chassis. In some configurations, closed chassis diapers may also have manually tearable side seams. The side seams may be configured as butt-type seams or overlapping side seams.
During the manufacturing process, a closed chassis diaper may be manufactured from a blank cut to a particular configuration and size. Manufacturing processes may involve some type of sealing step to create side seams in the diapers. For example, after being fully assembled, the blank may be folded along a central transverse area and the sides of the front and rear panels are seamed together to form a closed chassis diaper. In other processes, the side seams may be formed by folding the chassis in a crotch portion so that longitudinal side regions of the front portion and rear portion are superposed to form seaming areas, which are then treated with ultrasonic energy to sever the material in the seaming area in a first area while simultaneously bonding the material of the seaming area in a marginal area adjacent the first area to form a flangeless seam.
In some manufacturing configurations, the seaming and folding operations may be performed automatically on a processing wheel having a plurality of folding stations and associated seaming mechanisms. Various types of such processing wheels have been described in U.S. Patent Publication No. 2008/0083489 and U.S. Pat. Nos. 5,779,831 and 7,322,925. The processing wheels provide the ability to produce training pants a high rate of speed. However, reconfiguring various components of the processing wheel to change manufacturing operations for different sizes of absorbent articles can be onerous. For example, some components of the processing wheel may require realignment, which can be time consuming and expensive. For instance, different size folding stations may be needed to accommodate a different sized diaper. Such different sized folding stations may need to be realigned with the seaming stations. In addition, different sized folding stations may also require changes in the physical locations of operating stations, such as the discharge station, located adjacent the processing wheel.